Dose detection for a medication delivery device

ABSTRACT

The present disclosure relates to a dose detection system in combination with a medication delivery device. In one aspect, the system includes a module body adapted to be removably attached to the actuator of a medication delivery device, and one or more magnetic sensing elements attached to said module body. The system detects the amount of rotation of a magnetic ring of said one or more dipoles of a medication delivery device relative to the magnetic sensing elements during dose delivery when the module is attached to the device.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application is a continuation of U.S. patent application Ser. No.17/238,307, filed Apr. 23, 2021, which is a continuation of U.S. patentapplication Ser. No. 17/119,624, filed Dec. 11, 2020, which is acontinuation of U.S. patent application Ser. No. 16/488,721, filed Aug.26, 2019, which is the National stage of International Application No.PCT/US2018/019156, filed Feb. 22, 2018, which claims the benefit of U.S.Provisional Application Nos. 62/552,556, filed Aug. 31, 2017,62/539,106, filed Jul. 31, 2017, and 62/464,662, filed Feb. 28, 2017,each of the applications listed above in its entirety is hereinincorporated by reference.

TECHNICAL FIELD

The present disclosure relates to an electronic dose detection systemfor a medication delivery device, and illustratively to an electronicdose detection module adapted to removably attach to a proximal endportion of a medication delivery device. Alternatively, the dosedetection module could be integral to the medication delivery device.The dose delivery detection system is operable to detect the amount of adose of medication delivered by the medication delivery device and/orthe type of drug contained in the medication delivery device.

BACKGROUND

Patients suffering from various diseases must frequently injectthemselves with medication. To allow a person to conveniently andaccurately self-administer medicine, a variety of devices broadly knownas pen injectors or injection pens have been developed. Generally, thesepens are equipped with a cartridge including a piston and containing amulti-dose quantity of liquid medication. A drive member is movableforward to advance the piston in the cartridge to dispense the containedmedication from an outlet at the distal cartridge end, typically througha needle. In disposable or prefilled pens, after a pen has been utilizedto exhaust the supply of medication within the cartridge, a userdiscards the entire pen and begins using a new replacement pen. Inreusable pens, after a pen has been utilized to exhaust the supply ofmedication within the cartridge, the pen is disassembled to allowreplacement of the spent cartridge with a fresh cartridge, and then thepen is reassembled for its subsequent use.

Many pen injectors and other medication delivery devices utilizemechanical systems in which members rotate and/or translate relative toone another in a manner proportional to the dose delivered by operationof the device. Accordingly, the art has endeavored to provide reliablesystems that accurately measure the relative movement of members of amedication delivery device in order to assess the dose delivered. Suchsystems may include a sensor which is secured to a first member of themedication delivery device, and which detects the relative movement of asensed component secured to a second member of the device.

The administration of a proper amount of medication requires that thedose delivered by the medication delivery device be accurate. Many peninjectors and other medication delivery devices do not include thefunctionality to automatically detect and record the amount ofmedication delivered by the device during the injection event. In theabsence of an automated system, a patient must manually keep track ofthe amount and time of each injection. Accordingly, there is a need fora device that is operable to automatically detect the dose delivered bythe medication delivery device during an injection event. Further, thereis a need for such a dose detection device to be removable and reusablewith multiple delivery devices. In other embodiments, there is a needfor such a dose detection device to be integral with the deliverydevice.

It is also important to deliver the correct drug. A patient may need toselect either a different drug, or a different form of a given drug,depending on the circumstances. If a mistake is made as to which drug isin the medication delivery device, then the patient will not be properlydosed, and records of dose administration will be inaccurate. Thepotential for this happening is substantially diminished if a dosedetection device is used which automatically confirms the type of drugcontained by the medication delivery device.

SUMMARY

In one embodiment, a dose detection system is adapted for a medicationdelivery device. The medication delivery device includes a substantiallyelongate housing and an injectable medication held by the housing. Thehousing has a proximal end portion and a distal end portion. The dosedetection system includes a magnet ring with one or more dipolesconfigured to produce a magnetic field. The magnet ring is fixedlycoupled to a dose setting member located at or near the proximal endportion of the medication delivery device and rotatable relative to thehousing during dose setting and dose dispensing. An electronics assemblyincludes a processor and at least one magnetic sensor operably coupledto the processor and securely fixed relative to the processor to detectthe rotational position of the magnet ring. In dose setting, the magnetring is rotated relative to the housing. In dose dispensing, the atleast one magnetic sensor is distally moved closer to the magnet ring,the magnet ring rotates relative to the at least one magnetic sensor,the at least one magnetic sensor detects rotational movement of themagnet ring in order to generate position signals, and the processor isconfigured to receive the position signals in order to determine dataindicative of an amount of dose dispensed based on the position signal.

In another aspect, disclosed is a dose detection system having an add-onmodule adapted to be releasably mounted at or near a proximal end of amedication delivery device. The medication delivery device includes asubstantially elongate housing, an injection drive mechanism adapted toexpel a dose amount of medication from a contained reservoir, and amagnet ring producing a magnetic field. The magnet ring is coupled to adosing setting member located at or near an end portion of themedication delivery device and adapted to rotate relative to the housingduring dose setting and/or dispensing of the dose amount of medication.An amount of movement of the dose setting member can be indicative ofthe size of a set dose amount and/or a dispensed dose amount. The magnetring comprising one or more dipoles. The add-on module includes a sensorsystem including at least one magnetic sensor to determine magneticfield values from the magnet ring. A processor configured to determine,when the add-on module is mounted on the medication delivery device, onthe basis of detected values from the at least one magnetic sensor arotational position and/or a rotational movement of said magnet ring.The rotational position and/or a rotational movement of the magnet ringcorresponds to the dispensed dose amount.

In a further aspect, there is provided a dose detection system for amedication delivery device. The medication delivery device includes anelongated housing extending between a proximal portion and a distalportion about an axis, and an actuator located at said proximal portion.A magnetic component is located at the proximal portion of saidelongated housing. The device includes a clutch. The dose control systemincludes a module body to removably attach to the actuator. The modulebody is adapted to engage actuator to allow a user to set, via themodule body, a dose amount of medication to be dispensed. The modulebody is adapted to engage the actuator to allow a user to apply an axialforce via a portion of the module body to release a clutch in themedication delivery device. An electronics assembly comprising aprocessor and one or more magnetic sensors in communication with theprocessor. At an initial zero position without said axial force appliedto the portion of the module body the one or more magnetic sensors andthe magnetic component are at a first distance relative to one another,and at said initial zero position with said axial force applied to theportion of the module body the one or more magnetic sensors and themagnetic component are at a second distance relative to one another.

In another embodiment, a dose detection system includes a module adaptedand configured to be removably attached to a proximal portion of amedication delivery device. The system includes a magnetic componentlocated at the proximal portion of said elongated housing that isrotatable during dose delivery. The medication delivery device includesan actuator at the proximal portion of the medication delivery device.The actuator is rotatable about an axis of rotation of the medicationdelivery device for dose setting and dose delivery. The axis iscentrally located along the medication delivery device. The moduleincludes a module body configured to be coaxially mounted on, and engagein co-rotation with, the actuator. The module is configured to beremovably attached to the actuator, and the module body defines acavity. An electronics assembly is located within the cavity of themodule body, and the electronics assembly comprises a single magneticsensor. The single magnetic sensor is located on the axis, and thesingle magnetic sensor is movable axially along said axis relative tothe magnetic component during dose delivery.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present disclosure will become moreapparent to those skilled in the art upon consideration of the followingdetailed description taken in conjunction with the accompanying figures.

FIG. 1 is a perspective view of an exemplary medication delivery devicewith which the dose detection system of the present disclosure isoperable.

FIG. 2 is a cross-sectional perspective view of the exemplary medicationdelivery device of FIG. 1.

FIG. 3 is a perspective view of the proximal portion of the exemplarymedication delivery device of FIG. 1.

FIG. 4 is a partially-exploded, perspective view of the proximal portionof the exemplary medication delivery device of FIG. 1, together with adose delivery detection system of the present disclosure.

FIG. 5 is a side, diagrammatic view, partially in cross section, of adose detection system module according to another exemplary embodimentattached to the proximal portion of a medication delivery device.

FIG. 6 is a cross-sectional view of a module of a dose deliverydetection system according to an exemplary embodiment attached to theproximal portion of a medication delivery device.

FIG. 7 is a top, diagrammatic view showing rotation sensors positionedto detect magnetic sensed elements attached to a dose setting member inaccordance with an exemplary embodiment.

FIG. 8 is a perspective view of the dose setting member of FIG. 7including the magnetic sensed elements.

FIG. 9 is a perspective view of an alternate embodiment of a magneticdose delivery detection system.

FIGS. 10A-B and 11A-B show yet other exemplary embodiments of dosedelivery detection systems utilizing magnetic sensing.

FIGS. 12A-D and 13A-G show exemplary embodiments of a dose detectionsystem utilizing inductive sensing.

FIGS. 14-17 show an exemplary embodiment of a keying system useful witha dose type delivery system.

FIG. 18 is a cross-sectional view of a module of a dose detection systemaccording to another embodiment, shown attached to the proximal portionof a medication delivery device.

FIG. 19 is a diagrammatic view showing the positioning of a sensor andsensed component useful in an exemplary embodiment of a dose detectionsystem.

FIG. 20 is a schematic view showing the dose detection system of FIG.19.

FIG. 21 is a graph showing the output responses for the dose detectionsystem of FIG. 19.

FIG. 22 is cross-sectional view of a dose detection system according toanother embodiment, in which the sensor and sensed element areintegrated into a medication delivery device.

FIGS. 23A-C show in diagrammatic views an exemplary embodiment of a dosedetection system utilizing optical sensing of the rotation and/orposition of a skirt relative to a sensor component.

FIGS. 24A-B show in diagrammatic views another exemplary embodiment of adose detection system utilizing optical sensing of the rotation and/orposition of a flange relative to a sensor component.

FIGS. 25A-C shows an exemplary embodiment of a dose detection systemutilizing capacitive sensing.

FIG. 26 is a cross-sectional view of a further exemplary medicationdelivery device of the present disclosure.

FIG. 27 is a perspective view of an exemplary medication delivery deviceof the present disclosure.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the invention is thereby intended.

The present disclosure relates to sensing systems for medicationdelivery devices. In one aspect, the sensing system is for determiningthe amount of a dose delivered by a medication delivery device based onthe sensing of relative rotational movement between a dose settingmember and an actuator of the medication delivery device. The sensedrelative angular positions or movements are correlated to the amount ofthe dose delivered. In a second aspect, the sensing system is fordetermining the type of drug contained by the medication deliverydevice. By way of illustration, the medication delivery device isdescribed in the form of a pen injector. However, the medicationdelivery device may be any device which is used to set and to deliver adose of a medication, such as an infusion pump, bolus injector or anauto injector device. The medication may be any of a type that may bedelivered by such a medication delivery device.

Devices described herein, such as device 10, may further comprise amedication, such as for example, within a reservoir or cartridge 20. Inanother embodiment, a system may comprise one or more devices includingdevice 10 and a medication. The term “medication” refers to one or moretherapeutic agents including but not limited to insulins, insulinanalogs such as insulin lispro or insulin glargine, insulin derivatives,GLP-1 receptor agonists such as dulaglutide or liraglutide, glucagon,glucagon analogs, glucagon derivatives, gastric inhibitory polypeptide(GIP), GIP analogs, GIP derivatives, oxyntomodulin analogs,oxyntomodulin derivatives, therapeutic antibodies and any therapeuticagent that is capable of delivery by the above device. The medication asused in the device may be formulated with one or more excipients. Thedevice is operated in a manner generally as described above by apatient, caregiver or healthcare professional to deliver medication to aperson.

An exemplary medication delivery device 10 is illustrated in FIGS. 1-4as a pen injector configured to inject a medication into a patientthrough a needle. Pen injector 10 includes a body 11 comprising anelongated, pen-shaped housing 12 including a distal portion 14 and aproximal portion 16. Distal portion 14 is received within a pen cap 18.Referring to FIG. 2, distal portion 14 contains a reservoir or cartridge20 configured to hold the medicinal fluid to be dispensed through itsdistal outlet end during a dispensing operation. The outlet end ofdistal portion 14 is equipped with a removable needle assembly 22including an injection needle 24 enclosed by a removable cover 25. Apiston 26 is positioned in reservoir 20. An injecting mechanismpositioned in proximal portion 16 is operative to advance piston 26toward the outlet of reservoir 20 during the dose dispensing operationto force the contained medicine through the needled end. The injectingmechanism includes a drive member 28, illustratively in the form of ascrew, axially moveable relative to housing 12 to advance piston 26through reservoir 20.

A dose setting member 30 is coupled to housing 12 for setting a doseamount to be dispensed by device 10. In the illustrated embodiment, dosesetting member 30 is in the form of a screw element operative to spiral(i.e., simultaneously move axially and rotationally) relative to housing12 during dose setting and dose dispensing. FIGS. 1 and 2 illustrate thedose setting member 30 fully screwed into housing 12 at its home or zerodose position. Dose setting member 30 is operative to screw out in aproximal direction from housing 12 until it reaches a fully extendedposition corresponding to a maximum dose deliverable by device 10 in asingle injection.

Referring to FIGS. 2-4, dose setting member 30 includes a cylindricaldose dial member 32 having a helically threaded outer surface thatengages a corresponding threaded inner surface of housing 12 to allowdose setting member 30 to spiral relative to housing 12. Dose dialmember 32 further includes a helically threaded inner surface thatengages a threaded outer surface of sleeve 34 (FIG. 2) of device 10. Theouter surface of dial member 32 includes dose indicator markings, suchas numbers that are visible through a dosage window 36 to indicate tothe user the set dose amount. Dose setting member 30 further includes atubular flange 38 that is coupled in the open proximal end of dialmember 32 and is axially and rotationally locked to dial member 32 bydetents 40 received within openings 41 in dial member 32. Dose settingmember 30 further includes a collar or skirt 42 positioned around theouter periphery of dial member 32 at its proximal end. Skirt 42 isaxially and rotationally locked to dial member 32 by tabs 44 received inslots 46.

Dose setting member 30 therefore may be considered to comprise any orall of dose dial member 32, flange 38, and skirt 42, as they are allrotationally and axially fixed together. Dose dial member 32 is directlyinvolved in setting the dose and driving delivery of the medication.Flange 38 is attached to dose dial member 32 and, as described later,cooperates with a clutch to selectively couple dial member 32 with adose button 56. Skirt 42 provides a surface external of body 11 toenable a user to rotate the dial member 32 for setting a dose.

Skirt 42 illustratively includes a plurality of surface features 48 andan annular ridge 49 formed on the outer surface of skirt 42. Surfacefeatures 48 are illustratively longitudinally extending ribs and groovesthat are circumferentially spaced around the outer surface of skirt 42and facilitate a user's grasping and rotating the skirt. In analternative embodiment, skirt 42 is removed or is integral with dialmember 32, and a user may grasp and rotate dose button 56 and/or dosedial member 32 for dose setting. A user may grasp and rotate the radialexterior surface of one-piece dose button 56′ (shown in FIG. 27), whichalso includes a plurality of surface features, for dose setting.

Delivery device 10 includes an actuator 50 having a clutch 52 which isreceived within dial member 32. Clutch 52 includes an axially extendingstem 54 at its proximal end. Actuator 50 further includes dose button 56positioned proximally of skirt 42 of dose setting member 30. In analternative embodiment, dose setting member 30 comprises one-piece dosebutton 56′, shown in FIG. 27. Dose button 56 includes a mounting collar58 (FIG. 2) centrally located on the distal surface of dose button 56.Collar 58 is attached to stem 54 of clutch 52, such as with aninterference fit or an ultrasonic weld, so as to axially and rotatablyfix together dose button 56 and clutch 52.

Dose button 56 includes a disk-shaped proximal end surface or face 60and an annular wall portion 62 extending distally and spaced radiallyinwardly of the outer peripheral edge of face 60 to form an annular lip64 there between. Proximal face 60 of dose button 56 serves as a pushsurface against which a force can be applied manually, i.e., directly bythe user to push actuator 50 in a distal direction. Dose button 56illustratively includes a recessed portion 66 centrally located onproximal face 60, although proximal face 60 alternatively may be a flatsurface. Similarly, one-piece dose button 56′ shown in FIG. 27 mayinclude the recessed portion 66 centrally located on proximal face 60 oralternatively may be a flat surface. A bias member 68, illustratively aspring, is disposed between the distal surface 70 of button 56 and aproximal surface 72 of tubular flange 38 to urge actuator 50 and dosesetting member 30 axially away from each other. Dose button 56 isdepressible by a user to initiate the dose dispensing operation.

Delivery device 10 is operable in both a dose setting mode and a dosedispensing mode. In the dose setting mode of operation, dose settingmember 30 is dialed (rotated) relative to housing 12 to set a desireddose to be delivered by device 10. Dialing in the proximal directionserves to increase the set dose, and dialing in the distal directionserves to decrease the set dose. Dose setting member 30 is adjustable inrotational increments (e.g., clicks) corresponding to the minimumincremental increase or decrease of the set dose during the dose settingoperation. For example, one increment or “click” may equal one-half orone unit of medication. The set dose amount is visible to the user viathe dial indicator markings shown through dosage window 36. Actuator 50,including dose button 56 and clutch 52, move axially and rotationallywith dose setting member 30 during the dialing in the dose setting mode.

Dose dial member 32, flange 38 and skirt 42 are all fixed rotationallyto one another, and rotate and extend proximally of the medicationdelivery device 10 during dose setting, due to the threaded connectionof dose dial member 32 with housing 12. During this dose setting motion,dose button 56 is rotationally fixed relative to skirt 42 bycomplementary splines 74 of flange 38 and clutch 52 (FIG. 2), which areurged together by bias member 68. In the course of dose setting, skirt42 and dose button 56 move relative to housing 12 in a spiral mannerfrom a “start” position to an “end” position. This rotation relative tothe housing is in proportion to the amount of dose set by operation ofthe medication delivery device 10.

Once the desired dose is set, device 10 is manipulated so the injectionneedle 24 properly penetrates, for example, a user's skin. The dosedispensing mode of operation is initiated in response to an axial distalforce applied to the proximal face 60 of dose button 56. The axial forceis applied by the user directly to dose button 56. This causes axialmovement of actuator 50 in the distal direction relative to housing 12.

The axial shifting motion of actuator 50 compresses biasing member 68and reduces or closes the gap between dose button 56 and tubular flange38. This relative axial movement separates the complementary splines 74on clutch 52 and flange 38, and thereby disengages actuator 50, e.g.,dose button 56, from being rotationally fixed to dose setting member 30.In particular, dose setting member 30 is rotationally uncoupled fromactuator 50 to allow back-driving rotation of dose setting member 30relative to actuator 50 and housing 12. The dose dispensing mode ofoperation may also be initiated by activating a separate switch ortrigger mechanism.

As actuator 50 is continued to be axially plunged without rotationrelative to housing 12, dial member 32 screws back into housing 12 as itspins relative to dose button 56. The dose markings that indicate theamount still remaining to be injected are visible through window 36. Asdose setting member 30 screws down distally, drive member 28 is advanceddistally to push piston 26 through reservoir 20 and expel medicationthrough needle 24 (FIG. 2).

During the dose dispensing operation, the amount of medicine expelledfrom the medication delivery device is proportional to the amount ofrotational movement of the dose setting member 30 relative to actuator50 as the dial member 32 screws back into housing 12. The injection iscompleted when the internal threading of dial member 32 has reached thedistal end of the corresponding outer threading of sleeve 34 (FIG. 2).Device 10 is then once again arranged in a ready state or zero doseposition as shown in FIGS. 2 and 3.

The start and end angular positions of dose dial member 32, andtherefore of the rotationally fixed flange 38 and skirt 42, relative todose button 56 provide an “absolute” change in angular positions duringdose delivery. Determining whether the relative rotation was in excessof 360° is determined in a number of ways. By way of example, totalrotation may be determined by also taking into account the incrementalmovements of the dose setting member 30 which may be measured in anynumber of ways by a sensing system.

Further details of the design and operation of an exemplary deliverydevice 10 may be found in U.S. Pat. No. 7,291,132, entitled MedicationDispensing Apparatus with Triple Screw Threads for Mechanical Advantage,the entire disclosure of which is hereby incorporated by referenceherein. Another example of the delivery device is an auto-injectordevice that may be found in U.S. Pat. No. 8,734,394, entitled “AutomaticInjection Device With Delay Mechanism Including Dual Functioning BiasingMember,” which is hereby incorporated by reference in its entirety,where such device being modified with one or more various sensor systemsdescribed herein to determine an amount of medication delivered from themedication delivery device based on the sensing of relative rotationwithin the medication delivery device.

The dose detection systems use a sensing component and a sensedcomponent attached to members of the medication delivery device. Theterm “attached” encompasses any manner of securing the position of acomponent to another component or to a member of the medication deliverydevice such that they are operable as described herein. For example, asensing component may be attached to a member of the medication deliverydevice by being directly positioned on, received within, integral with,or otherwise connected to, the member. Connections may include, forexample, connections formed by frictional engagement, splines, a snap orpress fit, sonic welding or adhesive.

The term “directly attached” is used to describe an attachment in whichtwo components, or a component and a member, are physically securedtogether with no intermediate member, other than attachment components.An attachment component may comprise a fastener, adapter or other partof a fastening system, such as a compressible membrane interposedbetween the two components to facilitate the attachment. A “directattachment” is distinguished from a connection where thecomponents/members are coupled by one or more intermediate functionalmembers, such as the way dial member 32 is coupled in FIG. 2 to the dosebutton 56 by a clutch 52.

The term “fixed” is used to denote that an indicated movement either canor cannot occur. For example, a first member is “fixed rotationally”with a second member if the two members are required to move together inrotation. In one aspect, a member may be “fixed” relative to anothermember functionally, rather than structurally. For example, a member maybe pressed against another member such that the frictional engagementbetween the two members fixes them together rotationally, while the twomembers may not be fixed together absent the pressing of the firstmember.

Various sensor systems are contemplated herein. In general, the sensorsystems comprise a sensing component and a sensed component. The term“sensing component” refers to any component which is able to detect therelative position of the sensed component. The sensing componentincludes a sensing element, or “sensor”, along with associatedelectrical components to operate the sensing element. The “sensedcomponent” is any component for which the sensing component is able todetect the position and/or movement of the sensed component relative tothe sensing component. For the dose delivery detection system, thesensed component rotates relative to the sensing component, which isable to detect the angular position and/or the rotational movement ofthe sensed component. For the dose type detection system, the sensingcomponent detects the relative angular position of the sensed component.The sensing component may comprise one or more sensing elements, and thesensed component may comprise one or more sensed elements. The sensorsystem is able to detect the position or movement of the sensedcomponent(s) and to provide outputs representative of the position(s) ormovement(s) of the sensed component(s).

A sensor system typically detects a characteristic of a sensed parameterwhich varies in relationship to the position of the one or more sensedelements within a sensed area. The sensed elements extend into orotherwise influence the sensed area in a manner that directly orindirectly affects the characteristic of the sensed parameter. Therelative positions of the sensor and the sensed element affect thecharacteristics of the sensed parameter, allowing the controller of thesensor system to determine different positions of the sensed element.

Suitable sensor systems may include the combination of an activecomponent and a passive component. With the sensing component operatingas the active component, it is not necessary to have both componentsconnected with other system elements such as a power supply orcontroller.

Any of a variety of sensing technologies may be incorporated by whichthe relative positions of two members can be detected. Such technologiesmay include, for example, technologies based on tactile, optical,inductive or electrical measurements.

Such technologies may include the measurement of a sensed parameterassociated with a field, such as a magnetic field. In one form, amagnetic sensor senses the change in a sensed magnetic field as amagnetic component is moved relative to the sensor. In anotherembodiment, a sensor system may sense characteristics of and/or changesto a magnetic field as an object is positioned within and/or movedthrough the magnetic field. The alterations of the field change thecharacteristic of the sensed parameter in relation to the position ofthe sensed element in the sensed area. In such embodiments the sensedparameter may be a capacitance, conductance, resistance, impedance,voltage, inductance, etc. For example, a magneto-resistive type sensordetects the distortion of an applied magnetic field which results in acharacteristic change in the resistance of an element of the sensor. Asanother example, Hall effect sensors detect changes in voltage resultingfrom distortions of an applied magnetic field.

In one aspect, the sensor system detects relative positions or movementsof the sensed elements, and therefore of the associated members of themedication delivery device. The sensor system produces outputsrepresentative of the position(s) or the amount of movement of thesensed component. For example, the sensor system may be operable togenerate outputs by which the rotation of the dose setting member duringdose delivery can be determined. A controller is operably connected toeach sensor to receive the outputs. In one aspect, the controller isconfigured to determine from the outputs the amount of dose delivered byoperation of the medication delivery device.

The dose delivery detection system involves detecting relativerotational movement between two members. With the extent of rotationhaving a known relationship to the amount of a delivered dose, thesensor system operates to detect the amount of angular movement from thestart of a dose injection to the end of the dose injection. For example,a typical relationship for a pen injector is that an angulardisplacement of a dose setting member of 18° is the equivalent of oneunit of dose, although other angular relationships are also suitable.The sensor system is operable to determine the total angulardisplacement of a dose setting member during dose delivery. Thus, if theangular displacement is 90°, then 5 units of dose have been delivered.

One approach for detecting the angular displacement is to countincrements of dose amounts as the injection proceeds. For example, asensor system may use a repeating pattern of sensed elements, such thateach repetition is an indication of a predetermined degree of angularrotation. Conveniently, the pattern may be established such that eachrepetition corresponds to the minimum increment of dose that can be setwith the medication delivery device.

An alternative approach is to detect the start and stop positions of therelatively moving member, and to determine the amount of delivered doseas the difference between those positions. In this approach, it may be apart of the determination that the sensor system detects the number offull rotations of the dose setting member. Various methods for this arewell within the ordinary skill in the art, and may include “counting”the number of increments to assess the number of full rotations.

The sensor system components may be permanently or removably attached tothe medication delivery device. In an illustrative embodiment, as leastsome of the dose detection system components are provided in the form ofa module that is removably attached to the medication delivery device.This has the advantage of making these sensor components available foruse on more than one pen injector.

In some embodiments, a sensing component is mounted to the actuator anda sensed component is attached to the dose setting member. The sensedcomponent may also comprise the dose setting member or any portionthereof. The sensor system detects during dose delivery the relativerotation of the sensed component, and therefore of the dose settingmember, from which is determined the amount of a dose delivered by themedication delivery device. In an illustrative embodiment, a rotationsensor is attached, and rotationally fixed, to the actuator. Theactuator does not rotate relative to the body of the medication deliverydevice during dose delivery. In this embodiment, a sensed component isattached, and rotationally fixed, to the dose setting member, whichrotates relative to the actuator and the device body during dosedelivery. The sensed component may also comprise the dose setting memberor any portion thereof. In an illustrative embodiment, the rotationsensor is not attached directly to the relatively rotating dose settingmember during dose delivery.

Referring to FIG. 5, there is shown in diagrammatic form a dose deliverydetection system 80 including a module 82 useful in combination with amedication delivery device, such as device 10. Module 82 carries asensor system, shown generally at 84, including a rotation sensor 86 andother associated components such as a processor, memory, battery, etc.Module 82 is provided as a separate component which may be removablyattached to the actuator.

Dose detection module 82 includes a body 88 attached to dose button 56.Body 88 illustratively includes a cylindrical side wall 90 and a topwall 92, spanning over and sealing side wall 90. By way of example, inFIG. 5 upper side wall 90 is diagrammatically shown havinginwardly-extending tabs 94 attaching module 82 to dose button 56. Dosedetection module 82 may alternatively be attached to dose button 56 viaany suitable fastening means, such as a snap or press fit, threadedinterface, etc., provided that in one aspect module 82 may be removedfrom a first medication delivery device and thereafter attached to asecond medication delivery device. The attachment may be at any locationon dose button 56, provided that dose button 56 is able to move anyrequired amount axially relative to dose setting member 30, as discussedherein.

During dose delivery, dose setting member 30 is free to rotate relativeto dose button 56 and module 82. In the illustrative embodiment, module82 is rotationally fixed with dose button 56 and does not rotate duringdose delivery. This may be provided structurally, such as with tabs 94of FIG. 5, or by having mutually-facing splines or other surfacefeatures on the module body 88 and dose button 56 engage upon axialmovement of module 82 relative to dose button 56. In another embodiment,the distal pressing of the module provides a sufficient frictionalengagement between module 82 and dose button 56 as to functionally causethe module 82 and dose button 56 to remain rotationally fixed togetherduring dose delivery.

Top wall 92 is spaced apart from face 60 of dose button 56 and therebyprovides a cavity 96 in which some or all of the rotation sensor andother components may be contained. Cavity 96 may be open at the bottom,or may be enclosed, such as by a bottom wall 98. Bottom wall 98 may bepositioned in order to bear directly against face 60 of dose button 56.Alternatively, bottom wall 98 if present may be spaced apart from dosebutton 56 and other contacts between module 82 and dose button 56 may beused such that an axial force applied to module 82 is transferred todose button 56. In another embodiment, module 82 may be rotationallyfixed to the one-piece dose button 56′, shown in FIG. 27.

In an alternate embodiment, module 82 during dose setting is insteadattached to dose setting member 30. For example, side wall 90 mayinclude a lower wall portion 100 having inward projections 102 thatengage with skirt 42 in a position underneath ridge 49. In thisapproach, tabs 94 may be eliminated and module 82 effectively engagesthe proximal face 60 of dose button 56 and the distal side of annularridge 49. In this configuration, lower wall portion 100 may be providedwith surface features which engage with the surface features of skirt 42to rotationally fix module 82 with skirt 42. Rotational forces appliedto housing 82 during dose setting are thereby transferred to skirt 42 byvirtue of the coupling of lower wall portion 100 with skirt 42.

Module 82 is disengaged rotationally from skirt 42 in order to proceedwith dose delivery. The coupling of lower wall portion 100 with skirt 42is configured to disconnect upon distal axial movement of module 82relative to skirt 42, thereby allowing skirt 42 to rotate relative tomodule 82 during dose delivery.

In a similar fashion, module 82 may be coupled with both dose button 56and skirt 42 during dose setting. This has the advantage of providingadditional coupling surfaces during rotation of the module in dosesetting. The coupling of the module 82 to the skirt 42 is then releasedprior to dose injection, such as by the axial movement of module 82relative to skirt 42 as dose delivery is being initiated, therebyallowing dose setting member 30 to rotate relative to module 82 duringdose delivery.

In certain embodiments, rotation sensor 86 is coupled to side wall 90for detecting a sensed component. Lower wall portion 100 also serves toreduce the likelihood that a user's hand inadvertently applies drag todose setting member 30 as it rotates relative to module 82 and housing12 during dose delivery. Further, since dose button 56 is rotationallyfixed to dose setting member 30 during dose setting, the side wall 90,including lower wall portion 100, provide a single, continuous surfacewhich may be readily grasped and manipulated by the user during dosesetting.

When the injection process is initiated by pressing down on the dosedetection module 82, dose button 56 and dose setting member 30 arerotationally fixed together. Movement of module 82, and therefore dosebutton 56, a short distance, for example less than 2 mm, releases therotational engagement and the dose setting member 30 rotates relative tomodule 82 as the dose is delivered. Whether by use of a finger pad orother triggering mechanism, the dose detection system is activatedbefore the dose button 56 has moved a sufficient distance to disengagethe rotational locking of the dose button 56 and the dose setting member30.

Illustratively, the dose delivery detection system includes anelectronics assembly suitable for operation of the sensor system asdescribed herein. A controller is operably connected to the sensorsystem to receive outputs from one or more rotational sensors. Thecontroller may include conventional components such as a processor,power supply, memory, microcontrollers, etc. contained for example incavity 96 defined by module body 88. Alternatively, at least somecomponents may be provided separately, such as by means of a computer,smart phone or other device. Means are then provided to operably connectthe external controller components with the sensor system at appropriatetimes, such as by a wired or wireless connection.

An exemplary electronics assembly 120 comprises a flexible printedcircuit board (FPCB) having a plurality of electronic components. Theelectronics assembly comprises a sensor system including one or morerotation sensors 86 operatively communicating with a processor forreceiving signals from the sensor representative of the sensed relativerotation. The electronics assembly further includes a microcontrollerunit (MCU) comprising at least one processing core and internal memory.The system includes a battery, illustratively a coin cell battery, forpowering the components. The MCU includes control logic operative toperform the operations described herein, including detecting a dosedelivered by medication delivery device 10 based on a detected rotationof the dose setting member relative to the actuator. In one embodiment,the detected rotation is between the skirt 42 and the dose button 56 ofa pen injector.

The MCU is operative to store the detected dose in local memory (e.g.,internal flash memory or on-board EEPROM). The MCU is further operativeto wirelessly transmit and/or receive a signal representative of thedetected dose to a paired remote electronic device, such as a user'ssmartphone, over a Bluetooth low energy (BLE) or other suitable short orlong range wireless communication protocol. Illustratively, the BLEcontrol logic and MCU are integrated on a same circuit.

Much of the sensing electronics is contained in the cavity 96. However,the rotation sensor may be positioned in a variety of locations in orderto sense the relative movement of the sensed component. For example, therotation sensor may be located within cavity 96, within body 88 butoutside of the cavity 96, or in other locations of the body, such as onlower wall portion 100. The only requirement is that the rotation sensorbe positioned to effectively detect the rotational movement of thesensed component during dose delivery. In some embodiments, the rotationsensor is integral to the device 10.

One or more sensed elements are attached to the dose setting member 30.In one aspect, the sensed elements are directly attached to skirt 42 ofthe dose setting member. Alternatively, sensed elements may be attachedto any one or more of the dose setting components, including the dialmember, flange and/or skirt. The only requirement is that the sensedelement(s) be positioned to be sensed by the rotation sensor duringrelative rotational movement during dose delivery. In other embodiments,the sensed component comprises the dose setting member 30 or any portionthereof.

Further illustrative embodiments of a dose delivery detection system 80are provided in FIGS. 6-13. The embodiments are shown in somewhatdiagrammatic fashion, as common details have already been provided withrespect to FIGS. 1-5. In general, each embodiment includes similarcomponents of the dose detection module 82, including a body 88 having acylindrical upper wall 90 and a top wall 92. Each embodiment alsoincludes a lower wall 100, although it will be appreciated thatvariations on these components, including the absence of lower wall 100,are within the scope of the disclosure. Other parts common to theearlier descriptions herein include an electronics assembly 120contained within cavity 96 of module body 88, dose button 56, dosesetting member 32 and device housing 12. Further, in each embodiment thedose detection module 82 is diagrammatically shown as being attached tothe annular side wall 62 of dose button 56, although alternative formsand locations of attachment may be used. For example, dose detectionmodule 82 may be attached to dose button 56 and releasably attached toskirt 42 in some embodiments. Also, dose detection module 82 may beattached to one-piece dose button 56′, as shown in FIG. 27.

Each example also demonstrates the use of a particular type of sensorsystem. However, in some embodiments the dose detection system includesmultiple sensing systems using the same or different sensingtechnologies. This provides redundancy in the event of failure of one ofthe sensing systems. It also provides the ability to use a secondsensing system to periodically verify that the first sensing system isperforming appropriately.

In certain embodiments, as shown in FIG. 6, attached to top wall 92 ofmodule 82 is a finger pad 110. Finger pad 110 is coupled to top wall 92,which is in turn attached to upper side wall 90. Finger pad 110 includesa ridge 114 which extends radially inward and is received withincircumferential groove 116 of wall component 92. Groove 116 allows aslight axial movement between finger pad 110 and wall component 92.Springs (not shown) normally urge finger pad 110 upwardly away from wallcomponent 92. Finger pad 110 may be rotationally fixed to wall component92. Axial movement of finger pad 110 in the distal direction towardmodule body 88 as the injection process is initiated may be used totrigger selected events. One use of finger pad 110 may be the activationof the medication delivery device electronics upon initial pressing andaxial movement of the finger pad 110 relative to the module body 88 whendose injection is initiated. For example, this initial axial movementmay be used to “wake up” the device, and particularly the componentsassociated with the dose detection system. In one example, module 82includes a display for indication of information to a user. Such adisplay may be integrated with finger pad 110. MCU includes a displaydrive software module and control logic operative to receive andprocessed sensed data and to display information on said display, suchas, for example, dose setting, dosed dispensed, status of injection,completion of injection, date and/or time, or time to next injection.

In the absence of a finger pad, the system electronics may be activatedin various other ways. For example, the initial axial movement of module82 at the start of dose delivery may be directly detected, such as bythe closing of contacts or the physical engagement of a switch. It isalso known to activate a medication delivery device based on variousother actions, e.g., removal of the pen cap, detection of pen movementusing an accelerometer, or the setting of the dose. In many approaches,the dose detection system is activated prior to the start of dosedelivery.

Referring to FIGS. 6-8, dose detection module 82 operates using amagnetic sensing system 84. Two magnetic sensors 130 are positioned onlower wall portion 100 (illustratively the inside surface of lower wallportion 100) opposite skirt 42 of dose setting member 30. As for allembodiments, the number and location of the rotation sensor(s) and thesensed element(s) may be varied. For example, the embodiment of FIGS.6-8 may instead include any number of magnetic sensors 130 evenly orunevenly spaced around skirt 42. The sensed component 132 (FIGS. 7 and8) comprises a magnetic strip 134 secured to skirt 42, illustratively onthe interior of skirt 42. In the illustrative embodiment, the stripcomprises 5 pairs of north-south magnetic components, e.g., 136 and 138,each magnetic portion therefore extending for 36°. The magnetic sensors130 are positioned at a separation of 18° (FIG. 7), and read the digitalpositions of magnetic strip 132, and therefore of skirt 42, in a 2-bitgrey code fashion. For example, as the sensor detects the passage of aN-S magnetic pair, it is detected that skirt 42 has rotated 36°,corresponding to 2 units, for example, of dose being added (orsubtracted).

Other magnetic patterns, including different numbers or locations ofmagnetic elements, may also be used. Further, in an alternativeembodiment, a sensed component 133 is attached to or integral withflange 38 of dose setting member 30, as illustrated in FIG. 9.

As previously described, the sensing system 84 is configured to detectthe amount of rotation of the sensed element relative to the magneticsensors 130. This amount of rotation is directly correlated to theamount of dose delivered by the device. The relative rotation isdetermined by detecting the movements of the skirt 42 during dosedelivery, for example, by identifying the difference between the startand stop positions of skirt 42, or by “counting” the number ofincremental movements of skirt 42 during the delivery of medication.

Referring to FIGS. 10-11, there is shown an exemplary magnetic sensorsystem 150 including as the sensed element an annular, ring-shaped,bipolar magnet 152 having a north pole 154 and a south pole 156. Magnet152 is attached to flange 38 and therefore rotates with the flangeduring dose delivery. Magnet 152 may alternately be attached to dosedial 32 or other members rotationally fixed with the dose settingmember.

Sensor system 150 further includes a sensor 158 including one or moresensing elements 160 operatively connected with sensor electronics (notshown) contained within module 82. The sensing elements 160 of sensor158 are shown in FIG. 11A attached to printed circuit board 162 which isturn attached module 82, which is rotationally fixed to dose button 56.Consequently, magnet 152 rotates relative to sensing elements 160 duringdose delivery. Sensing elements 160 are operable to detect the relativeangular position of magnet 152. Magnetic sensor system 150 therebyoperates to detect the total rotation of flange 38 relative to dosebutton 56, and therefore the rotation relative to housing 12 during dosedelivery.

In one embodiment, magnetic sensor system 150 includes four sensingelements 160 equi-radially spaced within module 82. Alternative numbersand positions of the sensing elements may be used. For example, inanother embodiment, shown in FIG. 11B, a single sensing element 160 isused. Further, sensing element 160 in FIG. 11B is shown centered withinmodule 82, although other locations may also be used. In the foregoingembodiments, sensing elements 160 are shown attached within module 82.Alternatively, sensing elements 160 may be attached to any portion of acomponent rotationally fixed to dose button 56 such that the componentdoes not rotate relative to housing 12 during dose delivery.

For purposes of illustration, magnet 152 is shown as a single, annular,bipolar magnet attached to flange 38. However, alternativeconfigurations and locations of magnet 152 are contemplated. Forexample, the magnet may comprise multiple poles, such as alternatingnorth and south poles. In one embodiment the magnet comprises a numberof pole pairs equaling the number of discrete rotational, dose-settingpositions of flange 38. Magnet 152 may also comprise a number ofseparate magnet members. In addition, the magnet component may beattached to any portion of a member rotationally fixed to flange 38during dose delivery, such as skirt 42 or dose dial member 32.

The sensor system is alternatively exemplified in FIGS. 12-13 as aninductive sensor system 170. Sensor system 170 utilizes a sensed element171 comprising a metal band 172 attached to skirt 42 as the sensedelement. Sensor system 170 further includes a sensor 174 comprising oneor more sensing elements 176, such as the four independent antennas 178equi-radially spaced along the circumference of skirt 42. These fourantennas form two antenna pairs located 180 degrees apart and provide aratio-metric measurement of the angular position of skirt 42.

Metal band 172 is shaped such that one or more distinct rotationalpositions of skirt 42 relative to module 82 may be detected. Metal band172 has a shape which generates a varying signal upon rotation of skirt42 relative to antenna 178. Illustratively, FIGS. 13A-C show a bandpattern in which FIG. 13B shows a rotation of 90° from the position ofFIG. 13A, and FIG. 13C shows an additional 90° rotation. This patterngenerates a detected sine wave response upon rotation of skirt 42relative to module 82, as shown diagrammatically in FIG. 12D, in whichpositions a-d correlate to those shown in FIG. 12A.

FIG. 13D provides a schematic showing inductive sensor system 170incorporated into module 82 and skirt 42 of pen 10. Metal band 172 isshown attached to skirt 42. Antennas 178 are operably connected withelectronics 120 such that the antennas function to detect positions ofskirt 42 relative to module 82, and therefore relative to housing 12 ofpen 10, during dose delivery.

In the embodiment shown in FIGS. 12-13, inductive sensor system 170includes four sensing elements 176 comprising equi-radially spacedantennas 178 within module 82. Alternative numbers and positions of thesensing elements may be used. For example, another embodiment utilizes asingle antenna. In the illustrated embodiment, antennas 178 are shownattached within module 82. Alternatively, the antenna(s) may be attachedto any portion of a component rotationally fixed to dose button 56 suchthat the component does not rotate relative to housing 12 during dosedelivery.

For purposes of illustration, metal band 172 is shown as a single,cylindrical band attached to the exterior of skirt 42. However,alternate configurations and locations of metal band 172 arecontemplated. For example, the metal band may comprise multiple discretemetal elements. In one embodiment the metal band comprises a number ofelements equal to the number of discrete rotational, dose-settingpositions of skirt 42. The metal band in the alternative may be attachedto any portion of a component rotationally fixed to skirt 42 during dosedelivery, such as flange 38 or dial member 32. The metal band maycomprise a metal element attached to the rotating member on the insideor the outside of the member, or it may be incorporated into suchmember, as by metallic particles incorporated in the component, or byover-molding the component with the metal band.

The antennas 178 are shown schematically in FIG. 12A and structurally inFIGS. 13D and 13E as being round. An alternate configuration of theantennas is shown schematically in FIGS. 13F and 13G. Shown in FIG. 13Fis an “elongated antenna” 180 having a rectangular midsection 182 andsemi-circular ends 184. FIG. 13F depicts the position of antenna 180relative to metal band 186. This position corresponds to the peninjector being at rest with no axial displacement of the module as indelivering a dose. In FIG. 13G, antenna 180 is in the positioncorresponding to the module having been pressed to cause delivery of adose. The module and therefore antenna 180 has been displaced, downwardin FIG. 13G, relative to metal band 186. It is apparent that theelongated antenna 180 may provide a more uniform sensing of metal band186 as there is a more constant area of midsection 182 overlapping withthe metal band.

In one aspect, there is disclosed a modular form of the dose detectionsystem. The use of a removably attached module is particularly adaptedto use with a medication delivery device in which the actuator and thedose setting member both include portions external to the medicationdevice housing. These external portions allow for direct attachment ofthe sensing component to the actuator, such as a dose button, and asensed component to a dose setting member, such as a dose skirt, flange,or dial member, as described herein. In this regard, a “dose button” isused to refer more generally to a component of a medication deliverydevice which includes a portion located outside of the device housingand includes an exposed surface available for the user to use in orderto deliver a set dose. Similarly, a dose “skirt” refers more generallyto a component of a medication delivery device which is located outsideof the device housing and which thereby has an exposed portion availablefor the user to grasp and turn the component in order to set a dose. Asdisclosed herein, the dose skirt rotates relative to the dose buttonduring dose delivery. Also, the dose skirt may be rotationally fixed tothe dose button during dose setting, such that either the dose skirt ordose button may be rotated to set a dose. In an alternative embodiment,the delivery device may not include a dose skirt, and a user may graspand rotate the actuator (e.g., dose button) for dose setting. In someembodiments, with a dose detection module attached to the actuatorand/or the dose skirt, the dose detection module may be rotated tothereby rotate the dose setting member of the delivery device to set adose to be delivered.

It is a further feature of the present disclosure that the sensingsystem of dose detection system 80 may be originally incorporated into amedication delivery device as an integrated system rather than as anadd-on module.

The foregoing provides a discussion of various structures and methodsfor sensing the relative rotation of the dose setting member relative tothe actuator during dose delivery. In certain embodiments of medicationdelivery devices, the actuator moves in a spiral fashion relative to thepen body during dose setting. For illustrative purposes, this disclosuredescribes the dose detection system in respect to such a spiralingactuator. It will be appreciated by those skilled in the art, however,that the principles and physical operation of the disclosed dosedetection system may also be used in combination with an actuator thatrotates, but does not translate, during dose delivery. It will also beunderstood that the dose detection system is operable with otherconfigurations of medical delivery devices provided that the deviceincludes an actuator which rotates relative to a dose setting memberduring dose injection.

Detection systems may also be employed with the module for identifying acharacteristic of the drug to be administered by a pen injector. Peninjectors are used with a wide variety of drugs, and even with varioustypes of a given drug. For example, insulin is available in differentforms depending on the intended purpose. Insulin types includerapid-acting, short-acting, intermediate-acting and long-acting. Inanother respect, the type of the drug refers to which drug is involved,e.g., insulin versus a non-insulin medication, and/or to a concentrationof a drug. It is important not to confuse the type of drug as theconsequences may have serious implications.

It is possible to correlate certain parameters based on the type of adrug. Using insulin as an example, there are known limitations as to theappropriate amount of a dose based on factors such as which type ofinsulin is involved, how the type of insulin correlates to the timing ofthe dose, etc. In another respect, it is necessary to know which type ofdrug was administered in order to accurately monitor and evaluate atreatment method. In one aspect, there is provided a sensor system whichis capable of differentiating the type of drug that is to beadministered.

For determining the drug type, a module is provided which detects aunique identification of the type of drug contained in the medicationdelivery device. Upon mounting the module to the medication deliverydevice, e.g., pen injector, the module detects the type of drug andstores it in memory. The module is thereafter able to evaluate a drugsetting or delivery in view of the type of drug in the pen, as well asprevious dosing history and other information.

Referring to FIG. 14, pen injector 10 includes a sensor system 200comprising a sensed component 202 and a sensing component 204. Sensorsystem 200 is operable to identify distinct angular orientation ofsensed component 202 relative to pen injector 10. Sensor system 200 maybe of any type, such as previously described, whereby specific angularpositions can be identified.

In FIG. 14 there is shown a pen injector 10 including a housing 12, dosedial member 32, flange 38, clutch 52, dose button 56 and module 82.Sensed component 202 comprises one or more sensed elements 206 attachedto pen injector 10 in a manner which is uniquely identifiable. By way ofexample, sensed elements 206 are shown attached to skirt 42 and alwayshave the same orientation relative to skirt 42. Skirt 42 is rotatablerelative to housing 12, but has a unique, identifiable position relativeto housing 12 when in the “initial zero position” before any drug hasbeen dispensed from the pen injector. Similarly, the sensed elements 206may be attached to other rotatable members of the pen which have auniquely identifiable position at a relevant time, such as duringmounting of module 82 to pen injector 10. In this respect, sensedelements 206 may alternatively be attached, for example, to flange 38 ordial member 32.

Skirt 42 includes a slot 208 (FIG. 15) extending axially on the outsideof cylindrical skirt wall 210. The angular position of slot 208 relativeto the angular position of sensed elements 206 is predetermined tocorrespond with a selected type of drug. Referring to FIG. 15, slot 208is shown in the 9 o'clock position with skirt 42 at its initial, zerodose position. This position of slot 208 is assigned to represent a drugof a particular type. Alternatively, slot 208 is located in a differentangular position for the initial, zero dose position, such as at the 3o'clock position in FIG. 15. This position is then assigned to representa drug of a second type. Detection of the position of the sensedelements 206 relative to slot 208 is therefore useful to identify thedrug type contained by the pen injector 10.

Module 82 includes a lower wall 212 including an inner surface 214 (FIG.16). A tab 216 extends radially-inward of inner surface 214 and isconfigured to be received within slot 208. This condition is showndiagrammatically in FIG. 15. Tab 216 may be a simple projection of theinner surface, or may be provided as an arm able to flexradially-outwardly. In order to mount module 82 onto device 10, tab 216is aligned with slot 208 and the module is then advanced in thedirection of the device. Tab 216 is configured to assure properalignment with slot 208 by having a blunt front end 218. This isprovided to require tab 216 to be received within slot 208, rather thanimproperly riding over another location on the skirt.

FIG. 14 shows the module during installation with tab 216 receivedwithin slot 208. In FIG. 17, module 82 has advanced to its installedposition with tab 216 having moved out of slot 208. In this position,module 82 may be secured to dose button 56, for example by projection220, as previously described. Positioning tab 216 outside of slot 208allows for relative rotation between skirt 42 and module 82 afterinstallation.

The identification of the drug type results from the predeterminedorientation of the sensed elements relative to slot 208. For theembodiment of FIGS. 14-17, this means that the sensed elements areselectively positioned on skirt 42 to represent the type of drug. Inthat manner, whenever tab 216 is aligned with slot 208, the sensorsystem is operable to identify the relative angular relationship of thesensed element(s) and the module, and to derive the drug type therefrom.This detection may occur at any time that the tab and slot are aligned.Since this alignment is required at the time of mounting the module tothe skirt, it is convenient to detect the position at this time. Thismay be caused by triggering the sensor system in any suitable manner,such as by proximity sensors, sliding contacts, a spring biased switch,or by manual activation upon beginning installation of the module.

Once the module has been installed and the type of drug identified, thepen injector is ready for use. When desired, module 82 is removed fromthe pen injector and is available for use on another pen injector.During operation, the delivery of a dose will rotate skirt 42 relativeto module 82 such that at the end of a dose delivery the tab and slotmay not be aligned. This is of no consequence to the operation of thepen injector as the tab is axially displaced from slot 208 and maytherefore be in any angular position relative to skirt 42. However, tofacilitate removal of module 82, tab 216 includes a tapered back end222. This allows tab 216 to readily ride up over the outer surface 210of skirt 42, regardless of the angular position of the skirt. Theidentification of drug type has been described using a tab and slotalignment mechanism. However, other alignment structures or systems arealso contemplated.

This drug type detection is useful with a variety of sensor systemswhich are operable to detect a predetermined angular position of sensedelements relative to an alignment feature. These sensor systems includethose previously disclosed herein. It is a further aspect that this drugtype determination is readily combined with sensor systems for detectingthe amount of a dose delivery. The two systems may operate independentlyor in concert with one another.

In a particular aspect, the sensor system used for detecting dosedelivery is also used to identify the drug type. For example, FIGS.10-11 and related text describe a magnetic sensor system which includessensing elements 160 and a magnet 152 to determine the amount of adelivered dose. Magnet 152 has a unique configuration such that thesensor system is able to detect specific angular positions of magnet 152relative to the sensing elements. This same sensor system therefore maybe used in combination with an alignment feature, as described withrespect to FIGS. 14-17, to identify the drug type contained by the peninjector. The inductive sensor system of FIGS. 12-13 is another exampleof a sensor system useful for determining both drug type and dosedelivery.

Referring to FIGS. 18-21, an alternative drug and/or pen type detectionsystem 230 is provided. In this embodiment, sensor system 230 isprovided in connection with a module 232. Module 232 is removablyattached to pen injector 10 in the same keyed manner as described withrespect to module 82 in the embodiment of FIGS. 14-17. Sensor system 230comprises a sensed component 234 and a sensor 236. Sensor system 230 isoperable to identify distinct angular orientations of sensed component234 relative to pen injector 10. The identification of the drug and/orpen type results from the predetermined orientation of the sensedelement(s), as previously described. The sensor system is operable toidentify the relative angular relationship of the sensed element(s) tothe module, and to derive the medication and/or pen type therefrom.

The angular position of sensed component 234 is detected based on theunique angular profile of the sensed component. The term “unique angularprofile” is used to identify a configuration of the sensed component inwhich the one or more sensed elements 238 comprising sensed component234 enable the angular position of the sensed component to be uniquelyidentified for any predetermined angular position to be used by thesystem. A sensed component having such a unique angular profile isdemonstrated in FIGS. 19-21. FIG. 19 shows diagrammatically therelationship between one embodiment of sensed component 234 and sensor236. Sensed component 234 comprises a single sensed element 238 formedin a generally circular pattern.

Sensor 236 is shown in FIG. 20 as comprising opposed pairs of inductivecoil antennas 246 and 248, equi-radially positioned about the axis ofrotation 242 of actuator 244. The antennas represent A+/A− and a B+/B−pairings. Sensed component 234 is positioned as shown in FIG. 20configured to rotate around the axis of rotation 242. AC current flowsthrough the paired antennas 246 and 248 generating four separate andindependent AC magnetic fields.

As sensed element 234 passes by the antenna pairs, the magnetic fieldsof each antenna induce a circulating current (eddy current) on thesurface of the metal in sensed element 234. This eddy current causes itsown magnetic field, which opposes the original field generated by theantennas. As the metal of sensed element 234 moves closer to the antennacoils, a greater portion of the electromagnetic field produced by thatcoil is intercepted, and a lesser portion of the electromagnetic fieldsof the other antennas is intercepted. This means the eddy currentincreases as more electromagnetic field flux lines are intercepted, anddecreases as fewer flux lines are intercepted of other coils. Thischange in the eddy currents in each of the antennas changes theeffective inductance of each individual antenna. The system can measurethese changes in the inductance of each antenna 246 and 248 over timeand use that data from opposing coils 246 and 248 to cancel unwantedvariances due to temperature or mechanical tolerances. The result is twocontinuously changing wave forms 90 degrees out of phase as shown inFIG. 21.

The corresponding levels of the two output signals can be thencorrelated to the various rotational positions of sensed component 234relative to sensor 236 which allows for quadrature rotational sensing.The system provides response Data A and Data B from the A and B antennapairings 246 and 248, respectively. Sensor system 230 is shown in FIG.20 in the “0-position”. From the shape of sensed component 234 and fromthe signal outputs, it is apparent that each relative rotationalposition of sensed component 234 has a unique signature of response, andthus the sensed component has a unique angular profile about axis ofrotation 242 of actuator 244.

The output signals are processed and decoded to produce the uniquesignature for a given position of sensed element 234. Such processingmay include signal processing to repeatedly sample the output or toconvert the analog signals shown in FIG. 21 into separate digital squarewaves also 90 degrees out of phase. Lookup tables may be used to comparethe current and previous positional information to decode the directionof movement. For example, if the last decoded value for the outputsignals A and B were 00 respectively, and the current value is 01, itmay be said that the sensed element has moved one half step in theclockwise direction. The number of degrees for a given “step” isdetermined by the sampling rate of the analog signal. Increasing thesampling rate results in increased rotational resolution as smallerchanges in angular position are detected. For detecting drug or devicetype, however, it is sufficient if the sensed component results in aunique signal output for any angular position which is correlated to adrug or device type, or any other information to be detected.

Sensor system 230 is configured to detect one or more angular positionsof sensed component 234 relative to sensor 236. A controller 250responsive to the one or more detected angular positions, and is therebyoperable to determine information concerning the medication deliverydevice 10.

In this illustrative embodiment, module 232 is attached to actuator 244in a keyed relationship placing module 232, and therefore sensor 236, ina predetermined angular position relative to actuator 244. This keyedrelationship, for example, may be provided in the same manner as for theembodiment of FIGS. 14-17, by having slot 208 of skirt 42 receiving tab216 of module 232 (FIG. 18).

The predetermined angular position of module 232 is correlated to thetype of medication delivery device 10, and/or the type of medicationcontained by medication delivery device 10. For example, the 0°-positionshown in FIG. 20 may indicate that the pen injector is a pen having aparticular capacity for medication, and the 90°-position may indicatethat the medication is a fast-acting insulin. The 180° position mayindicate, for example, that the medication delivery device is a peninjector containing a certain volume of fast-acting insulin. Thecorrelations may be stored in memory carried by module 232. Thecontroller is configured to determine the angular position of sensedcomponent 234 relative to sensor 236 contained by module 232, and toderive the correlated information about the medication delivery device.

In another illustrative embodiment, sensor system 230 is operable todetermine the amount of medication delivered by the medication deliverydevice. In accordance with this embodiment, the medication deliverydevice includes a dose setting member which rotates relative to the bodyof the medication delivery device during dose delivery. An actuator isaxially and rotatably fixed with the dose setting member in a firstoperating mode during dose setting. The actuator is non-rotatablerelative to the device body in a second operating mode during dosedelivery. Sensor system 230 detects the rotation of the sensed componentrelative to the module during dose delivery, and the controller derivesthe amount of medication delivered.

In a further embodiment, the sensor system of the medication deliverydevice is operable to determine both information concerning themedication delivery device itself, and the amount of medicationdelivered by the medication delivery device. In this embodiment, module232 is attached to the medication delivery device and sensor system 230detects the angular position of sensed component 234 to module 232. Thisposition is correlated to the type of medication delivery device, thetype of medication contained by the medication delivery device, or anyother desired information. The medication delivery device is then usedto deliver a medication. During delivery, sensor system 230 detects therotation of sensed component 234 relative to sensor 236 as an indicationof the amount of medication delivered.

Referring to FIG. 18, further exemplary details of medication deliverysystem 252 are provided. System 252 comprises medication delivery device10 including device body 11, dose dial member 32, flange 38, skirt 42,clutch 52 and dose button 56 in FIG. 18. Module 232 may be attached todose button 56 by projections 220 extending inwardly from module 232.With initial attachment, module 232 is oriented with respect to skirt 42by tab 216 being received within slot 208. In this orientation, theposition of sensed component 234 relative to sensor 236 is correlatedwith the type of medication and/or the type of medication deliverydevice, as previously described.

For dose delivery, module 232 and dose button 56 are advanced in thedistal direction with respect to skirt 42, to the position of FIG. 21.In this position, skirt 42, dose dial member 32 and flange 38 movetogether in rotation relative to dose button 56 as a dose of medicationis delivered.

Sensed component 234 as shown comprises a single sensed element providedas a metal band 254. As described with respect to FIGS. 19-21, metalband 254 has a unique angular profile surrounding the axis of rotation242. By way of example, sensed element 238 is shown attached to dosedial member 32. Dose dial member 32 is rotatable relative to device body11, but has a unique, identifiable position relative to device body 11when in the “initial zero position” before any drug has been dispensedfrom the medication delivery device. Similarly, sensed element 238 maybe attached to other rotatable members of the medication delivery devicewhich have a uniquely identifiable position at a relevant time, such asduring mounting of module 232 to medication delivery device 10. In thisrespect, sensed component 234 may alternatively be attached, forexample, to flange 38 or skirt 42.

The illustrative sensor system 230 is also useful as a system which isintegrated into a medication delivery device, rather than being providedas a removable module. Referring to FIG. 22, there is shown a medicationdelivery device 310 substantially the same as device 10 in FIGS. 1-4.Medication delivery device 310 includes device body 11 and dose settingmember 30 comprising dose dial member 32, flange 38, and skirt 42. Thesecomponents are configured to function as previously described. Actuator50 comprises clutch 52 and dose button 56 attached thereto. Dose button56 is rotationally fixed with dose setting member 30 during dosesetting. For dose delivery, this rotational fixing is disengaged, anddose setting member 30 rotates relative to dose button 56 in proportionto the amount of dose delivered.

Medication delivery device 310 differs from the device 10 of FIGS. 1-4in the inclusion of a dose detection system 312, comprising sensedcomponent 314 and sensor 316. Sensor 316 is integrated into dose button56. Dose button 56 includes base wall 318, perimetric wall 320, and topwall 322, and together they form compartment 324. Sensor 316 comprisesone or more sensor elements 326 supported within compartment 324.Similarly, one-piece dose button 56′ shown in FIG. 27 may containintegrated sensor 316 and compartment 324.

An electronics assembly 328 is also received within compartment 324 andis operably connected with sensor elements 326. Electronics assembly 328further includes a controller 330. Controller 328 is coupled with sensorelements 320 to receive the sensor output and to thereby determineinformation concerning the medication delivery device and/or itscontents.

Sensed component 314 is attached to dose setting member 30. As for theembodiment of FIGS. 18-21, sensed component 314 comprises a metal bandor other sensed element which has a unique angular profile. Sensedcomponent 314 is shown attached to dose dial member 32, but it may aswell be attached to other components of dose setting member 30. Sensor316 is positioned and configured to detect the relative angular positionof sensed component 314.

This embodiment differs from FIGS. 18-21 in that the components of dosedetection system 312 are integrated into medication delivery device 310.In other respects, the sensing operation proceeds as previouslydescribed, with the dose detection system operating to detect the typeof medication delivery device, the type of medication, and/or the amountof dose delivered by the medication delivery device, etc. In yet anotheralternative, sensed component 314 is integrated into medication deliverydevice 310, but sensor 316 is contained by a removable module aspreviously described.

Referring to FIGS. 23A-C, there is shown an alternative embodimentemploying optical sensing. As previously described, module 82 isattached to medication delivery device 10, which includes dose button 56and skirt 42. The sensed element comprises one or more detectable marks350 applied to the upper surface 352 of skirt 42. The marks maycomprise, for example, spots of visible or invisible ink attached toskirt 42. The sensor system comprises a camera assembly 354 mountedwithin compartment 96. Camera assembly 354 is positioned and includessuitable optics to track the detectable mark(s) throughout rotation ofskirt 42 relative to module 82.

In a similar embodiment also using optical sensing, shown in FIGS.24A-B, there again is provided a module 82 attached to medicationdelivery device 10. The sensed component comprises one or moredetectable marks 360 applied to the upper surface 368 of flange 38.Camera assembly 364 is positioned and includes suitable optics to trackthe detectable mark(s) 360 throughout rotation of flange 38 relative tomodule 82. For example, camera assembly 364 may include a lens 366positioned in alignment with a window (not shown) of dose button 56, andoptionally a notch 370 formed in tab 94 of side wall 90. Detectablemarks 360 may be provided in various patterns to facilitate monitoringof rotation of flange 38. It will be appreciated that either of theembodiments of FIGS. 23 and 24 could alternatively, or additionally, beused to detect an absolute relative position of the skirt or flangebased on the inclusion of unique detectable marks around the perimeterof the skirt or flange.

The sensor system is alternatively exemplified in FIGS. 25A-C as acapacitive sensor system 380. Sensor system 380 utilizes a sensedelement 382 comprising a metal band 384 attached to skirt 42. Sensorsystem 380 further includes a sensor 386 comprising one or more sensingelements, e.g. antennas or armatures 388, mounted to side wall 90opposite metal band 384. The metal band for example covers half of thecircumference of skirt 42 and creates capacitive coupling between eachpair of armatures while it rotates on the Z axis. The two armature pairs180° apart form two sensors in quadrature and provide a ratio-metricmeasurement of the angular position of the skirt.

Metal band 384 is shaped such that rotational positions of skirt 42relative to module 82 may be detected. Metal band 384 has a shape whichgenerates a varying signal upon rotation of skirt 42 relative toantennas 384. The shape of metal band 384 and the positions of thearmatures produce a sine wave response as skirt 42 rotates. A shield 390on the outside of module wall 90 is connected to the device ground 392and provides isolation of the sensor during operation.

For purposes of illustration, metal band 384 is shown as a single,cylindrical band extending halfway around the interior of skirt 42.However, alternate configurations and locations of metal band 384 arecontemplated. For example, the metal band may comprise multiple discretemetal elements. The metal band in the alternative may be attached to anyportion of a component rotationally fixed to skirt 42 during dosedelivery, such as flange 38 or dial member 32. The metal band maycomprise a metal element attached to the rotating member on the insideor the outside of the member, or it may be incorporated into suchmember, as by metallic particles incorporated in the component, or byover-molding the component with the metal band. In the embodimentillustrated in FIG. 27, dose button 56′ of the illustrated device 10 isone piece which combines both skirt 42 and the dose button 56 of FIGS.1-4. In this embodiment, with reference to FIGS. 11A and 11B, flange 38is attached to dose dial member 32 and cooperates with clutch 52 toselectively couple dose dial member 32 with the one-piece dose button56′. The radial exterior surface of one-piece dose button 56′ provides asurface external of body 11 to use in rotating the dial member 32.

The dose detection systems have been described by way of example withparticular designs of a medication delivery device, such as a peninjector. However, the illustrative dose detection systems may also beused with alternative medication delivery devices, and with othersensing configurations, operable in the manner described herein. Any ofthe devices described herein may comprise any one or more of medicationsdescribed herein, such as, for example, within the cartridge of thedevice.

What is claimed:
 1. A dose detection system adapted for a medicationdelivery device, the medication delivery device comprising asubstantially elongate housing, an injectable medication held by thehousing, the housing having a proximal end portion and a distal endportion, wherein the dose detection system comprises: a magnet ring withone or more dipoles configured to produce a magnetic field, wherein themagnet ring is fixedly coupled to a dose setting member located at ornear the proximal end portion of the medication delivery device androtatable relative to the housing during dose setting and dosedispensing, and an electronics assembly comprising a processor and atleast one magnetic sensor operably coupled to the processor and securelyfixed relative to the processor to detect a rotational position of themagnet ring, wherein: in dose setting the magnet ring is rotatedrelative to the substantially elongate housing of the medicationdelivery device, and in dose dispensing the at least one magnetic sensoris distally moved closer to the magnet ring, the magnet ring isconfigured to rotate relative to the at least one magnetic sensor, theat least one magnetic sensor is configured to detect the rotationalposition and/or a rotational movement of the magnet ring in order togenerate position signals, and the processor is configured to receivethe position signals in order to determine data indicative of an amountof dose dispensed based on the position signals.
 2. The dose detectionsystem as in claim 1, wherein the medication delivery device furthercomprises a rotatable dose skirt or a one-piece button coupled to thedose setting member and adapted to allow a user to set a dose amount ofmedication to be dispensed, and the electronics assembly being adaptedto engage the rotatable dose skirt or the one-piece button adapted toallow the user to set the dose amount of medication to be dispensed viathe electronics assembly.
 3. The dose detection system as in claim 1,wherein the magnet ring comprises a single dipole magnet.
 4. The dosedetection system as in claim 1, wherein the at least one magnetic sensorcomprises a plurality of magnetic sensors arranged such that a portionof each of the magnetic sensors is disposed to extend radially beyond anouter circumference of the magnetic ring.
 5. A dose detection systemcomprising: an add-on module adapted to be releasably mounted at or neara proximal end of a medication delivery device, the medication deliverydevice comprising a substantially elongate housing, a reservoircontaining a medication, an injection drive mechanism adapted todispense a dose amount of the medication from the reservoir, a dosesetting member, a magnet ring configured to produce a magnetic field,wherein the magnet ring is coupled to the dosing setting member, themagnetic ring located at or near an end portion of the medicationdelivery device and adapted to rotate relative to the housing duringdose setting and/or dispensing of the dose amount of the medication,wherein an amount of movement of the dose setting member beingindicative of a size of a set dose amount and/or a dispensed doseamount, the magnet ring comprising one or more dipoles, the add-onmodule comprising a sensor system including at least one magnetic sensorconfigured to determine magnetic field values from the magnet ring, anda processor configured to determine, when the add-on module is mountedon the medication delivery device, on the basis of determined magneticfield values from the at least one magnetic sensor a rotational positionand/or a rotational movement of the magnet ring, the rotational positionand/or the rotational movement of the magnet ring corresponding to thedispensed dose amount.
 6. The dose detection system of claim 5, whereinthe medication delivery device further comprises: a rotatable dose skirtor a one-piece button coupled to the dose setting member and adapted toallow a user to set the se dose amount of the medication, and the add-onmodule being adapted to engage the dose skirt or the one-piece button toallow the user to set, via the add-on module, the set dose amount of themedication.
 7. The dose detection system of claim 5, wherein the magnetring comprises a single dipole magnet.
 8. The dose detection system ofclaim 5, wherein the at least one magnetic sensor comprises a pluralityof magnetic sensors arranged such that a portion of the magnetic sensorsis disposed to extend radially beyond an outer circumference of themagnetic ring.
 9. A dose detection system for a medication deliverydevice, the medication delivery device comprising an elongated housingextending between a proximal portion and a distal portion about an axis,and an actuator located at said proximal portion, a magnetic componentlocated at the proximal portion of said elongated housing, and a clutch,wherein said dose detection system comprises: a module body to removablyattach to the actuator, the module body being adapted to engage theactuator to allow a user to set, via the module body, a dose amount ofmedication to be dispensed, the module body being adapted to engage theactuator to allow the user to apply an axial force via a portion of themodule body to release the clutch in the medication delivery device; andan electronics assembly comprising a processor and one or more magneticsensors in communication with the processor; wherein at an initial zeroposition without the axial force applied to the portion of the modulebody the one or more magnetic sensors and the magnetic component are ata first distance relative to one another, and at the initial zeroposition with the axial force applied to the portion of the module bodythe one or more magnetic sensors and the magnetic component are at asecond distance relative to one another.
 10. The dose detection systemof claim 9, wherein the magnetic component comprises a single dipolemagnet.
 11. The dose detection system of claim 9, wherein the seconddistance is less than the first distance.
 12. The dose detection systemof claim 9, wherein the module body is configured to be coaxiallymounted on, and engage in co-rotation with, the actuator.
 13. The dosedetection system of claim 9, wherein the module body defines a cavitycontaining the electronics assembly.
 14. The dose detection system ofclaim 9, wherein the axis is centrally located along the medicationdelivery device, and the one or more magnetic sensors comprises a singlemagnetic sensor, wherein the single magnetic sensor is located on theaxis, and the single magnetic sensor is movable axially along the axisrelative to the magnetic component during dose delivery.
 15. The dosedetection system of claim 9, wherein the actuator further comprises arotatable dose skirt and a push dose button positioned proximal to therotatable dose skirt, wherein when the push dose button is depressed theclutch in the medication delivery device is released.
 16. The dosedetection system of claim 9, wherein the actuator further comprises aone-piece dose button, wherein when the rotatable one-piece dose buttonis depressed the clutch in the medication delivery device is released.17. A dose detection system comprising a module adapted and configuredto be removably attached to a proximal portion of a medication deliverydevice, the system comprising: a magnetic component located at theproximal portion of the medication delivery device, the magneticcomponent is rotatable during dose setting and dose delivery, themedication delivery device including a reservoir of a medication, anactuator at the proximal portion of the medication delivery device, theactuator rotatable about an axis of rotation of the medication deliverydevice for dose setting and/or dose delivery, the axis centrally locatedalong the medication delivery device, the module including a module bodyconfigured to be coaxially mounted on, and engage in co-rotation with,the actuator; the module is configured to be removably attached to theactuator, the module body defining a cavity; and an electronics assemblylocated within the cavity of the module body, wherein the electronicsassembly comprises a single magnetic sensor, wherein the single magneticsensor is located on the axis, and the single magnetic sensor is movableaxially along the axis relative to the magnetic component during thedose delivery.
 18. The dose detection system of claim 17, wherein themedication delivery device includes a clutch, wherein the module body isadapted to engage the actuator to allow a user to apply an axial forcevia a portion of the module body to release the clutch in the medicationdelivery device.
 19. The dose detection system of claim 18, wherein theactuator further comprises a rotatable dose skirt and a push dose buttonpositioned proximal to the rotatable dose skirt, wherein when the pushdose button is depressed the clutch in the medication delivery device isreleased.
 20. The dose detection system of claim 18, wherein theactuator further comprises a one-piece dose button, wherein when therotatable one-piece dose button is depressed the clutch in themedication delivery device is released.
 21. The dose detection system ofclaim 17, further comprising a clutch, the module body being adapted toengage the actuator to allow a user to apply an axial force via aportion of the module body to release the clutch, wherein at an axialposition without the axial force applied to the portion of the modulebody the single magnetic sensor and the magnetic component are at afirst distance relative to one another, and at the axial position withthe axial force applied to the portion of the module body the singlemagnetic sensor and the magnetic component are at a second distancerelative to one another.
 22. The dose detection system of claim 21,wherein the actuator further comprises a rotatable dose skirt and a pushdose button positioned proximal to the rotatable dose skirt, wherein themodule body is configured to be coaxially mounted on, and engage inco-rotation with, the rotatable dose skirt.
 23. The dose detectionsystem of claim 22, wherein during dose setting the module body, therotatable dose skirt, and the push dose button move together relative toa housing of the medication delivery device in a spiral manner inproportion to a set dose amount.
 24. The dose detection system of claim23, wherein during dose delivery after the dose setting, when the userapplies the axial force via the portion of the module body, the pushdose button is moved distally relative to the rotatable dose skirt torelease the clutch.